Windshield wiper arm assembly



April ll, 1961 F. A. KROHM WINDSHIELD WIPER ARM ASSEMBLY Original FiledMarch 26, 1954 2 Sheets-Sheet 1 nl THIIHMH Il "I l. "lily fzNvElvToR.FRED A. KRoHM BY MMM/M' ATTORNEY April 11, 1961 F. A. KRQHM WINDSHIELDWIPER ARM ASSEMBLY 2 sheets-sheet 2 'Original Filed March 26, 1954 mm.www

N wmf@ WK j., 1A. M D n FW Y B nit WINDSHIELD WIPER ARM ASSEMBLY Fred A.Krohrn, Hobart, Ind., assignor to The Anderson Company, a corporation ofIndiana 4 Claims. (ci. '13g-6) This invention relates generally towindshield' wiper devices and more particularly is directed to a wiperarm and/or combination of an arm assembly with a wiper blade and amovement-modifying arm to provide an improved system or method of wipinga curved surface.

The windshields of automotive vehicles are being made longer and withcurved rearwardly extending extremities or wings to promote vision andstyling. In the trade, windshields of this character are referred to asthe wrap-around type.

The design of windshield structures now provided on lsome vehicles hasadvanced to an extent where conventional wipers are incapable ofsatisfactorily cleaning certain areas of a windshield particularly at oradjacent the curved wings. Some areas due to the narrow width andextreme curvature of the glass are not wiped at all by a conventionalwiper. In fact a conventional wiper blade operating through a true arcin approaching a wing will leave the windshield so that a portion of theblade will extend into space and/ or beyond the edges of the windshieldin which event only a small part of the wing is cleaned. This conditionresults in poor Visibility and, therefore, is detrimental to safedriving.

With the foregoing in mind, one of the principal objects of theinvention is to provide a unique method of utilizing wiper apparatuscomprising a wiper blade-carrying arm with means for reciprocating andpivoting the blade with respect to the longitudinal axis of the arm sothat the blade will be caused to readily conform to a particular portionof the windshield to be wiped.

More specifically, the arrangement is such that the blade, during acomplete stroke in one direction from a parked position, willprogressively move toward the drive shaft supporting the wiper arm,`andas the blade approaches the wing portion of the windshield it will bepivoted with respect to the arm so as to reach and wipe a prescribedarea which could not be wiped by a blade restricted for movement in atrue are by conventional apparatus. In other words, the invention oifersa means whereby the blade, during its oscillation across the windshield,will be caused to pivot with respect to the arm only at a predeterminedlocation as the blade also moves toward and away from the drive shaftsupporting the wiper arm.

More particularly an object of the invention is to provide a novelmethod utilizing apparatus comprising, among other things, a primary armhaving an inner section for attachment to a drive shaft, an intermediatesection pivotally connected to the inner section and an extensible orslidable outer section provided with a pivotal connector for supportinga blade; a secondary or p movement-modifying arm having one end pivotedto the extensible section of the primary arm and its other end arrangedfor attachment to a pin on a mounting so that when the primary arm isoscillated across a windshield by the drive shaft the extensible sectionand blade carried by the connector thereon will reciprocate length` tesPater wise with respect to the inner and intermediate arm sections.

Other objects and advantages of the invention will become apparent afterthe description hereinafter set forth is considered in connection withthe drawings annexed hereto.

In the drawings:

Figure l is a longitudinal section of the primary arm structure' andalso shows the mode of connecting it to a drive shaft;

Figure 2 is'a bottom view showing the operative relationship of theprimary arm and secondary or movement-modifying arm;

Figure 3 is a partial enlarged longitudinal sectional View of theprimary arm structure and illustrates the action which takes place whenan actuator on the arm is moved into engagement with an abutment meanson the arm;

Figure 4 is a partial bottom view of the primary arm structure and showsthat the lconnector for supporting the blade is pivoted with respect tothe extensible arm section when the actuator is operated by the abutmentmeans;

Figure 5 is a bottom View of a fitting which is employed to facilitateconnection and adjustment of the secondary arm with respect to a bearingwhich supports the drive shaft;

Figure 6 is a view with a portion in section for the purpose ofdepicting the manner in which the fitting is attached to the bearing;

Figure 7 is a lfront view of the assembly shown in Figure 6 withportions in section to illustrate details of construction;

Figure 8 is a longitudinal View which illustrates the manner in whichthe secondary arm is connected to the iitting; a

Figure 9 is a top View of the extensible arm section;

Figure l0 is a sectional View taken substantially on line 10-10 ofFigure 1 illustrating the details of the operative relationship betweenthe connector for supporting the blade and the extensible arm section;

Figure ll is a transverse section taken substantially on line 11-11 ofFigure l; y

Figure l2 is a transverse section taken through an appropriate part ofthe apparatus depicting details of construction;

Figures 13 and 14 are transverse sectional views respectively taken onlines 13-13 and 14-14 of Figure l;

Figure l5 is a front view of a windshield showing the dilferentpositions of the wiper apparatus and wiper blade associated therewith;and

Figure 16 is a partial longitudinal sectional view taken through awindshield showing dilerent positions of the connected to the innersection, and an extensible or outer section 3 slidably mounted on theintermediate section.

The inner arm section of the primary arm is preferably provided with apair of relatively movable clutch members 4 and a nut 5 for detachablysecuring the arm in any one of a number of predetermined xed positionson a drive shaft 6, the latter of which is rotatably supported in amounting 7 which extends through the cowl of a vehicle body.

The intermediate section 2 of the primary arm is preferably formed toprovide an elongate chamber 8. A helical spring 9 is housed within thischamber and one end of the spring is connected to one of the clutchmembers on the inner section and its other end to a cross pin on theintermediate section for urging the intermediate and outer arm sectionsas a unit toward awindshield.

The intermediate section is further preferably provided Withan elongaterecess lit andY a groove 12 of adepth somewhat less than they depthofthe recess. The recess is formed with a longitudinal extending shoulder13 which in eiiect constitutes a continuation of the base wall of thegroove i2. A portion of one side of the intermediate section ispreferably removed to provide clearance for an integral lug ifi on theextensible arm section and a bearing therefor, the bearing beingdisposed in the same plane as the shoulder 13 and the base wall of thegroove l2 so that substantiallyv continuous track means are provided forthe extensible section.

The .intermediate section 2 is further provided with yieldable abutmentmeans preferably inthe form of an elongate generally U-shaped-springhaving legs 15 with oifset ends 16 which project outwardly into a pairof holes 17 provided therefor in the side walls of the intermediatesection. The spring is interposed between the base wall of the chamberand the cross-pin it? to locate a bridge portion i3 connecting the legsl5 in a predetermined position adjacent the inner end of the recess il.The abutment means may be constructed in other ways than as hereiniilustrated, but the one shown oers a setup whereby its onset ends maybe detachably received in more than one pair of holes in theintermediate section as illustrated so that the bridge portion iti maybe located in different positions for a purpose which will be describedsubsequently.

The extensible arm section 3 is preferably provided with alongitudinally extending groove i9 in its underside for slidablyreceiving a connecting rod 2t?. As clearly" shown in Figures 3 and 9 theextensible section is further provided with an elongate generallyrectangular opening 2l in its inner end and an adjacent opening 22located between the opening 2i and the groove i9. An actuator 23 ispivotally mounted in the rectangular opening 2l by means of a pivot 24extending through the bottom central portion of the actuator and throughthe extensible section. A link 25 is disposed in the opening 22 and hasits forward end pivotally connected by a pin 26 to the connecting rod2t) and its rear offset end 27 to the forward lower corner portion ofthe actuator by a pin 2S. it will be noted that the forward end of the.actuator is preferably bifurcated and that the pin 28 extendstransversely therethrough including the link and that the outer end ofthe link is similarly provided with a bifurcation which receives theinner end of the connecting rod Z0, the pin 2S extending transverselythrough the rod and bifurcation. it will be noted that the pivotalconnections between the actuator, extensible section and link arelocated in the plane of the extensible section and that the connectionbetween the iink and rod is located in a different plane so as toobtain, among other things, a desirable leverage action. The actuator isfurther preferably provided with rounded or bevelled end portions and anotch 29 which is adapted to receive the bridge portion i8 of theabutment means as shown in Figure 3 and in a manner which will beexplained subsequently.

A connector 30 is pivotally mounted on the free end of the extensiblesection. This connector may be designed and constructed as desired, butas herein illustrated preferably includes a channel and a cross pinwhich are adapted to cooperate with a suitable attachment provided on awiper blade. The connector is provided with an offset constituting alink 3i which is arranged atan obtuse angle with respect to thelongitudinal axis of the connector. ri`he end of the link is providedwith a slot 32 and the connecting rod is angled from the extensiblesection and provided with an upturned offset 33 which slides in the slotwhen the blade is pivoted with respect tothe 1ongitudinal axis of theprimary arm by the connecting rod through the agency of the actuator.

A cover 3d in the form of an elongate channel is detachably connected tothe underside of the intermediate arm section and, among other things,serves to hold the extensible section and connecting rod operativelyassociated with one another with the extensible section nesting in theintermediate section and the connecting rod in the extensible sectionfor guiding purposes and to reduce the over-all thickness of the primaryarm. lt will be noted that the extensible section and connecting rodactually slidably bear on the cover. The cover may be detachably securedto the intermediate section by any suitable means but as herein shown apin 35 extends through the side walls of the cover and through theintermediate section. it will be noted that an inner portion of thecover is cut away so as to provide clearance for the lug 14 extendingoutwardly fromrthe inner end of the extensibleV arm section. It shouldbe further noted that the inner end 36 of the cover as shown in Figure 3terminates at a predetermined location with reference to the bridgeportion 18 of the abutment means.

It is to be understood that it is not necessary that the majorportion ofthe connecting rod nest in the extensible arm section because if founddesirable it may belocated between the lower surface of the extensiblesection and the upper surface of the bottom wall of the cover 34.

Also, in some instances, it may be desirable to locate the connectingrod in a groove disposed in the upper side of the extensible section orbetween the upper surface of this section and the base wall of thegroove 12 in the intermediate section. Furthermore, means other than acover such as l34 may be utilized to hold the extensible section andconnecting rod in operative relationship with respect to one another andthe intermediate arm section.

The `arrangement above described is preferably such that when theextensible arm section is moved inwardly a sufficient distance the innerrounded end of the actuator will engage the bridge portion 18 of thespring, and when the extensible section is moved further inwardly therounded end of the actuator will engage and cam the spring back untilthe bridge portion 18 moves into the notch 29,. whereupon the actuatoris released from the inner end 36 of the cover-to permit the actuatorand link 25 to take the dotted-line positions exemplified in Figure 3when the extensible section is caused to travel inwardly stil-l further.When the extensible section is moved outwardly the rounded forward endof the actuator will cam against the bridge portion 1S of the spring andcause the actuator to pivot back to the full-line position illustratedin Figures 1 and 3. Whenever the actuator is operated by the spring theconnecting rod 20 causes the connector 30 and blade carried thereby topivot with respect to the longitudinal axis of the extensible armsection.

It is to be understood that means other than a cover may be employed todetermine when the actuator 2.3 is

Yallowed to pivot when engaged by the bridge 18 of the spring orabutment means. Moreover, it is to be understood that provision may bemade to cause the actuator to pivot at more than one location during thetravel of the extensible section with respect to the intermediatesection so -as to actuate the connecting rod to pivot the blade atpredetermined areas of the windshield.

Attention isdirected to the important fact that the actuator cannot bepivoted while it is confined for movement by the cover.V In other words,the actuator cannot be pivoted to reciprocate the connecting rod so thatthe latter will pivot theblade until the `actuator clears the inner end36 of the cover. This setup positively assures that the blade will notbe pivoted with respect to the longitudinal axis of the arm until thearm reaches a predetermined position during its travel across awindshield.

As depicted in Figures 2, 7 and 8, the secondary or movement-modifyingarm includes, among other things, an elongate, arm 37and.a link 38. Theouterend of the arm 37 is pivotally connected to the lug 14 on theextensible section of the primary arm and the link 38 is pivotallyconnected to the inner end of the secondary arm 37. The link ispreferably adjustably connected to an elongate fitting 39, the innerenlarged end of which is preferably detachably connected to the driveshaft mounting 7 by and between a pair of nuts 40 and 41 threaded on themounting. The outer end of the fitting is provided with a slot 42through which the shaft 43 of a bolt assembly extends so that the link38 may be adjustably secured to the fitting for the purpose of varyingthe travel of the extensible section of the primary arm which carriesthe wiper blade. The inner enlarged end of the fitting is provided withan aperture through which the threaded portion of the drive shaftmounting extends and is further provided with serrations 44 whichcooperate with corresponding serrations 45 preferably provided on theupper end or surface of the nut 40 to firmly secure the fitting in placeafter adjustment. With this arrangement, the travel of the lextensiblearm can be varied to suit different installation requirements. Theadjustments between the link and fitting and between the fitting and theshaft mounting all contribute toward control of the extensible armsection. The fact that the complete apparatus is supported on the driveshaft and mounting therefor also facilitates installation.

In view of the foregoing, and referring to Figures 15 and 16 of thedrawing, the wiper apparatus is shown in a parked position and indifferent operative positions. When the blade is moved upwardly andtoward the right the blade will take the path shown by the unshadedarea. More specifically in this regard, the blade is held againstpivotal movement until it reaches or approaches the dotted-line position46 at the beginning of the bent wing portion of the windshield, and asit swings further over to position 47 the movement-modifying armgradually pulls the extensible arm section inwardly, and as the actuator23 clears the inner end 36 of the cover the bridge 18 of the abutmentmeans will ride into the notch 29 of the actuator to operate theactuator and thereby pull the connecting rod 20 inwardly to pivot theblade so that the blade will substantially wrap itself around a portionof the wing of the windshield. The blade will traverse the same path onits return movement. In addition to wiping a windshield at the placesdescribed, the blade is prevented from banging against the windshieldframe.

The importance of the invention is perhaps best exemplilied in Figure 15where the blade, if mounted for movement through a true arc in theconventional way, would cause the blade to travel the path indicated bythe dotted lines 48 and cause at least a portion of the blade to swing othe windshied into space as indicated by the dotted-line position 49.

Having thus described my invention, it is obvious that variousmodifications may be made in the same without 6 departing from thespirit of the invention; and, therefore, I do not wish to be understoodas limiting myself to the exact forms, constructions, arrangements andcombinations of parts herein shown and described.

I claim:

l. The method of wiping a windshield having a convex surface comprisingoscillating an elongate wiper yblade-and-arm assembly transversely ofits length along the convex surface of the windshield about a fixed axiswhile progressively varying the distance between the wiper blade andsaid fixed axis throughout a predetermined stroke of oscillation andangularly adjusting the wiper blade relative to the arm in a pathsubstantially parallel to the surface of the windshield through an outerportion only of said stroke of oscillation.

2. The method of wiping a windshield having a convex surface comprisingoscillating an elongate wiper blade-and-arm assembly transversely of itslength along the convex surface of the windshield about a fixed axiswhile progressively varying the distance between the wiper blade and4`said fixed axis throughout a predetermined stroke of oscillation andangularly adjusting the wiper blade relative to the arm in a pathsubstantially parallel to the surface of the windshield through at leasta portion of said stroke of oscillation.

3. The method of wiping a windshield having a convex surface comprisingoscillating an elongate wiper blade transversely of its length along theconvex surface of the windshield about a fixed axis while progressivelyvarying the distance between the wiper blade and said fixed axisthroughout its stroke of oscillation and angularly adjusting the wiperblade, as it moves through an outer portion only of said stroke ofoscillation, relative to a straight linejoining said fixed axis and apredetermined fixed point on said blade.

4. The method of wiping a curved windshield having a frontal portion anda wing portion comprising oscillating an elongate wiper bladetransversely of its length along the curved surface of the windshieldabout a fixed axis while progressively varying the distance between thewiper blade and said fixed axis throughout its stroke of oscillation andangularly adjusting the wiper blade, as it moves over said wing portionof said windshield, relative to a straight line joining said fixed axisand a predetermined fixed medial point on said blade.

References Cited in the file of this patent UNITED STATES PATENTS2,185,572 Sawyer Jan. 2, 1940 2,691,186 Oishei Oct. 12, 1954 2,775,780Pisano Jan. 1, 1957 FOREIGN PATENTS 1032.359 France Mar. 25, 1953

1. THE METHOD OF WIPING A WINDSHIELD HAVING A CONVEX SURFACE COMPRISINGOSCILLATING AN ELONGATE WIPER BLADE-AND-ARM ASSEMBLY TRANSVERSELY OF ITSLENGTH ALONG THE CONVEX SURFACE OF THE WINDSHIELD ABOUT A FIXED AXISWHILE PROGRESSIVELY VARYING THE DISTANCE BETWEEN THE WIPER BLADE ANDSAID FIXED AXIS THROUGHOUT A PREDETERMINED STROKE OF OSCILLATION ANDANGULARLY ADJUSTING THE WIPER BLADE RELATIVE TO THE ARM IN A PATHSUBSTANTIALLY PARALLEL TO THE SURFACE OF THE WINDSHIELD THROUGH AN OUTERPORTION ONLY OF SAID STROKE OF OSCILLATION.